Starlin's statement "confirms" just GOTG and TA2 easily enough. All you have to do is use common sense:

1) Starlin was upset that Marvel used Thanos without his permission. He was ready to sue.
2) Marvel sat down for talks with Starlin. Now Starlin is happy again, and he knows Thanos will be in GOTG and TA2. Why? Because they're now paying the residuals he's owed....why else? The last thing they want is Thanos getting held up in trademark court for years of legal wrangling.

So if Marvel intends to use Thanos beyond GOTG and TA2, they damn well would've informed Starlin (and his lawyers), or else there'd be hell to pay. Cappice?